1. Field of the Invention
The present invention relates to a novel corannulene compound and an organic light-emitting device.
2. Description of the Related Art
An organic light-emitting device includes: an anode; a cathode; and a thin film containing a fluorescent organic compound or a phosphorescent organic compound, the thin film being interposed between the anode and the cathode. An electron and a hole are injected from the respective electrodes. Then, an exciton of the fluorescent organic compound or of the phosphorescent organic compound is generated. The device utilizes light to be radiated when the exciton returns to its ground state.
Recent progress in an organic light-emitting device is remarkable. The organic light-emitting device is characterized in that it can be turned into a thin, lightweight light-emitting device which: provides high luminance at a low applied voltage; and has the diversity of a luminous wavelength and high-speed responsiveness. The characteristic suggests the potential of the light-emitting device to find use in a wide variety of applications.
Japanese Patent Application Laid-Open No. 2002-324678 describes an example of a light-emitting material in which pyrene is substituted by a benzene ring and an example of an organic light-emitting device using it. The document describes that a device having good light-emitting property and good durability is provided.
However, the device of Japanese Patent Application Laid-Open No. 2002-324678 has low external quantum efficiency, and the document has no specific description concerning the durable lifetime of the device.
In addition, conventionally known organic light-emitting devices including, but not limited to, the device of Japanese Patent Application Laid-Open No. 2002-324678 each require optical output with additionally high luminance or high conversion efficiency. In addition, each of the devices still involves many problems in terms of durability such as a change with time due to long-term use and deterioration due to, for example, an atmospheric gas containing oxygen or humidity. Further, when one attempts to apply each of the devices to a full-color display or the like, each of blue light, green light, and red light must be emitted at a good color purity. However, problems concerning the emission have not been sufficiently solved yet.